This invention relates generally to the field of ophthalmic surgery and more particularly to a pumping chamber for use with a surgical handpiece.
During many surgical procedures, particularly microsurgical procedures such as ophthalmic surgery, small mechanical devices or probes are inserted into the surgical field. These different probes have a variety of functions. For example, small scissors are often to used to cut fibrous tissue. Guillotine-type or rotary cutters are used to remove the vitreous from the posterior chamber of an eye or for opening the anterior capsule for cataract surgery. Prior to the present invention, these devices have all used pneumatic or electric drivers. Pneumatic drivers use air pressure pulses to force a plunger against a spring. When the pressure pulse decays, the spring forces the plunger back to its original starting point, thereby imparting reciprocal motion to the plunger. With these types of surgical systems, the pressure pulse is generated in the control console and can travel as far as two meters down the connecting pneumatic tubing before entering the probe. Compliance in the tubing causes degradation of the pressure pulse. Electrical drivers contain miniature electrical motors that can be heavy and relatively expensive, making them less desirable for disposable probes.
Therefore, a need continues to exist for a handpiece driver that is lighter, less expensive than the prior art drivers and that delivers sharp, consistent drive pulses, with faster cut rates and/or rise time.